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The high-temperature deformation and damage behavior of ultrafine-grained (UFG) Cu produced by equal channel angular pressing (ECAP) were investigated and compared at two strain rates of 10^-2 s^-1 and 10^-3 s^-1. It is found that the strain rate has an obvious effect on the deformation and damage behavior of UFG Cu, especially at the testing temperatures near and above recrystallization. In general, the lower the strain rate, more universally grain coarsening takes place, the lower the yield stress and steady flow stress are, and more aggravated the degree of deformation damage becomes.

The grain size of as-extruded AZ31 magnesium alloy was refined by isothermal annealing pretreatment through orthogonal experiment. By using the Gleeble-3800 thermal simulator, the compression superplasticity of as-extruded AZ31 magnesium alloy was studied. The high strain rate superplastic compression was realized. The process parameters of the superplastic compression were established and the mechanism of the superplastic deformation was analyzed. The effects of deformation temperature and strain rate on the superplastic flow were investigated. The results indicated that at 250°C–300°C and strain rate at 1×10^-2s^-1, the true strain values were all more than 2.03. As the temperature was 300°C and the strain rate was 1×10^-2s^-1–1×10 s^-1, the true strain values were all more than 2.18. The results showed that the as-extruded AZ31 magnesium alloy being refined presented good compression superplasticity. The main mechanism for the superplastic compressive deformation of the as-extruded AZ31 magnesium alloy was grain-boundary sliding, meanwhile, dynamic recrystallization also played a harmonious role during the superplastic deformation.

A low-cost P/M processing route has been developed for the production of randomly packed hollow sphere structures (RHS). A fluidized-bed process allows mass production of iron-based green spheres with a large choice of possible sphere diameters and wall thicknesses. The individual sphere diameter may vary between 0.5 and 10 mm with wall thicknesses ranging from 20 to 1000 µm. From these green spheres, hollow sphere structures are formed in a special die. The subsequent consolidation and joining of the individual spheres is accomplished in one sintering step. Thus significant cost savings can be achieved over former approaches, where cellular metallic structures were obtained by brazing or sinter bonding of single metallic spheres.

With this method, test specimens from stainless steel 316L have been manufactured and their physical properties, i.e. density and compression strength, were measured.

The effect of equal channel angular pressing (ECAP) on high-temperature compressive deformation and damage behavior of LY12 Al alloys was studied. It is found that the ECAP and temperature have noticeable effects on the compressive deformation and damage behavior of the LY12 Al alloys, especially in the case that the testing temperatures are near and above recrystallization. With the increase of ECAP passage, grains are refined significantly and the plastic deformation ability of the LY12 Al alloys is thus enhanced obviously. With increasing compressive temperature, obvious grain coarsening occurs in ECAPed samples and the plastic deformation capacity is greatly strengthened.